Down on the Hitch Pin Web

[Ron Nossaman]

Hi Bill,

Why this changed with the move, I couldn't say, but here is my understanding
of what is happening with the bolt adjustment. It isn't a bearing problem,
there's already plenty of that. In the B, and D too I think, the plate in
that area is flexible enough to absorb the string energy and kill the
sustain. Tightening the bolt down adds enough rigidity (raises plate
impedance at rear termination) to let the soundboard get the string energy
instead of the plate. You are only deflecting the plate a few thousandths of
an inch here, so you shouldn't notice any difference in the bearing but the
power and sustain improve pretty substantially. I'm sorry, I don't have
absolute deflection figures, it's somewhere between when the sound begins to
improve, and when the plate breaks. Err on the conservative side, needless
to say.
 
Ron
 

>The pianist then mentions a technician once worked a miracle with a similar
>dead treble by adjusting the bolt which ties to the bell. (He has no idea
>in which direction.) I crank crank up 3/4 of a turn until the bolt is
>loose. The pianist plays, but nobody hears any difference. I go back down
>to the starting point, and beyond by 1/2 turn until it begins to require
>uncomfortable amounts of torque. In neither case does the dial indicator
>show a change in db. But going down, they all say, yeah that sounds more
>like it.
>
>What's going on here? Is there a real effect? There is of course Rick
>Davenport's oft-told story of Heiner Seinwald doing exactly this same thing
>(or recommending that Rick do the same). I can understand not seeing an
>immediate change in db on the way upwards, as  the plate might not
>immdiately react to take new upward freedom. But what gives in the
>direction down when the db doesn't show a change and the musicians hear a
>difference? Is the pianist simply getting used to the newly filed hammers?
>
>I less interested in suggestion on voicing (or for that matter, new
>strings/hammers which it badly needs, or even discreet sound reinforcing)
>than on people's specific experience with reseting the htich pin web at the
>bell.
>But I'll consider all comments (including the one about the santero priest).
>
>TIA
>
>Bill Ballard, RPT
>New Hampshire Chapter, PTG
>
>"May you work on interesting pianos."
>Ancient Chinese Proverb
>
>

 Ron